Hello,

Well I'm having problems with my carb again. The biggest issue right now is cold starts, when I try to start the car for the first time in the morning I'm usually out there for 10-15 mins trying to get it started and today I completely ran the battery and jumper battery dead trying to start it. Most of the threads I've found on here that talk about hard cold starts end up being a leaky fuel bowl, so I took the carb off a couple weeks ago, put it over some paper and filled it with gas to see if I could find any leaks.. I left it all day but nothing leaked out, and I had already covered the plugs with JB weld when I was doing a rebuild earlier..

I've tried every combination I can think of to get it started, sometimes I pump the gas once or twice before starting and then every few seconds that I'm turning it over, sometimes I hold the gas in slightly as I'm turning it over, etc but nothing gets it started any quicker. I usually turn it over for 5-10 seconds at a time, then wait a bit and turn it over another 5-10 seconds, and usually about the 4th or 5th time it will start to catch a little bit and if I'm lucky it will actually start.

If it does start, it usually runs pretty well, and after shutting it back off it will easily start within 1-2 seconds of cranking as long as I start it within a few hours of shutting it off. The only strange thing is it usually idles at about 750-1000 rpm right after starting, but after driving a block or two it will creep up to 1200 or so, then after another couple blocks it will be at 1500 or more. Fluttering the gas will not bring the idle down. However, sometimes while idling high like this the ses light will randomly come on and the idles will drop to a steady 750 or so for the rest of my drive until I turn it off. I have followed the instructions in my Haynes manual to check engine codes, but none ever come up. In fact the last few times I have tried it won't even flash the all-clear code 12 signal - the SES light just stays on without blinking.

I did change from an auto to manual transmission last summer without doing anything with the ECM, so I guess that may affect the idle somewhat - could this be part of the problem? I heard the ECM could be re-programmed for a manual but I'm unsure how to do that.. Well if anyone has any thoughts about how to get it to start better I'd really appreciate any help... Thanks!

 

Check your choke and choke pulloff. The choke should be closed when cold-after the throttle has been opened to engage it. The choke pulloff should open the choke slightly as soon as the engine provides enough vacuum.

Visually check to see that your choke closes when the engine is cold and the throttle is opened-'bout half-way of a full mash of the pedal. It should stay closed until the engine is started, then slowly open as the engine runs and be full open after a couple minutes.

Test the choke pulloff by pressing the plunger in and holding your finger over the vacuum nipple. The plunger should stay in place until you release your finger.

Your ECM isn't doing anything that should affect cold weather starts.

 

I got the car started tonight with the help of some starter fluid, I checked out the choke and it was mostly closed before I started it - maybe 1/8 inch open or so. After 3 or 4 minutes it was fully open. The ses light had already come on by that point, so the idle stayed nice and low while I drove it around for about 10 minutes. When I pulled up outside my place, the ses light turned back off and the idle jumped up to about 2000. I tried playing with the throttle a bit but it wouldnt back off.. after about another 5 minutes the car stuttered a bit and the ses light came back on, the idle dropped down to about 1200 and stayed there. The choke was open the whole time, and the choke pulloff plunger appears to be working.

 

When it's idling high ensure that the throttle is not being held off of the curb idle set screw.

Check the power wire to the ECM. It runs along the driver's side fenderwell into the ECM harness. It is connected to the battery by a single wire connector 'bout a foot off the positive battery post. When the SES light stays on and doesn't respond to probing with key in 'run' it could mean the ECM has lost power. When the ECM loses power the MCS will not cycle in the carb (you won't hear it clicking) and the carb will run full rich.